191099220643 has 4 divisors (see below), whose sum is σ = 192474035320. Its totient is φ = 189724405968.

The previous prime is 191099220607. The next prime is 191099220677. The reversal of 191099220643 is 346022990191.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 346022990191 = 6173 ⋅56054267.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191099220643 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 191099220593 and 191099220602.

It is not an unprimeable number, because it can be changed into a prime (191079220643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 687407130 + ... + 687407407.

It is an arithmetic number, because the mean of its divisors is an integer number (48118508830).

Almost surely, 2^191099220643 is an apocalyptic number.

191099220643 is a deficient number, since it is larger than the sum of its proper divisors (1374814677).

191099220643 is a wasteful number, since it uses less digits than its factorization.

191099220643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1374814676.

The product of its (nonzero) digits is 209952, while the sum is 46.

The spelling of 191099220643 in words is "one hundred ninety-one billion, ninety-nine million, two hundred twenty thousand, six hundred forty-three".